1. Technical Field
The present invention relates to a projector and a method for controlling the projector.
2. Related Art
As an invention relating to detection of the position of a pointer that points a projected image, JP-A-2014-74825, for example, discloses a projector. The projector is so configured that an imaging section thereof captures an image of an area including an image projected on a projection surface. When a light emitting pen that is the pointer is present on the projection surface, infrared light emitted by the light emitting pen from a light emitting diode is captured with the imaging section. The projector analyzes an image generated by the capturing operation to detect the position of the light emitting pen on the projection surface. When the light emitting pen is moved and an image of a line that connects the positions of the moved light emitting is projected, an image of a line corresponding to the trajectory along which the light emitting pen has been moved can be projected.
The projector can adjust the area of projected video images by adjustment of the distance to the projection surface. When the distance from the projector to the projection surface is prolonged, the size of a projected image increases, whereas when the distance from the projector to the projection surface is shortened, the size of a projected image decreases. When the distance from the projector to the projection surface is shortened, the distance to the light emitting pen, which points the projection surface, is also shortened, and when the distance from the light emitting pen to the projector is shortened, a light flux incident on the imaging section per unit area increases. When the light flux incident on the imaging section increases, the projector, which detects the region of the light emitted by the light emitting pen on an image captured by the imaging section to locate the position of the light emitting pen, undesirably detects a larger region as the region of the emitted light than an actual region. When a larger region than an actual region is detected as the region of the emitted light, as described above, the position of the light emitting pen is detected with lower accuracy.